/*
 * ConnectBot: simple, powerful, open-source SSH client for Android
 * Copyright 2007 Kenny Root, Jeffrey Sharkey
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.iiordanov.pubkeygenerator;

import android.graphics.Paint;
import android.text.AndroidCharacter;

/**
 * @author Kenny Root
 */
public abstract class EastAsianWidth {
    public static EastAsianWidth getInstance() {
        if (PreferenceConstants.PRE_FROYO)
            return PreFroyo.Holder.sInstance;
        else
            return FroyoAndBeyond.Holder.sInstance;
    }

    /**
     * @param charArray
     * @param i
     * @param position
     * @param wideAttribute
     */
    public abstract void measure(char[] charArray, int start, int end,
                                 byte[] wideAttribute, Paint paint, int charWidth);

    private static class PreFroyo extends EastAsianWidth {
        private static final int BUFFER_SIZE = 4096;
        private float[] mWidths = new float[BUFFER_SIZE];

        @Override
        public void measure(char[] charArray, int start, int end,
                            byte[] wideAttribute, Paint paint, int charWidth) {
            paint.getTextWidths(charArray, start, end, mWidths);
            final int N = end - start;
            for (int i = 0; i < N; i++)
                wideAttribute[i] = (byte) (((int) mWidths[i] != charWidth) ?
                        AndroidCharacter.EAST_ASIAN_WIDTH_WIDE :
                        AndroidCharacter.EAST_ASIAN_WIDTH_NARROW);
        }

        private static class Holder {
            private static final PreFroyo sInstance = new PreFroyo();
        }
    }

    private static class FroyoAndBeyond extends EastAsianWidth {
        @Override
        public void measure(char[] charArray, int start, int end,
                            byte[] wideAttribute, Paint paint, int charWidth) {
            AndroidCharacter.getEastAsianWidths(charArray, start, end - start, wideAttribute);
        }

        private static class Holder {
            private static final FroyoAndBeyond sInstance = new FroyoAndBeyond();
        }
    }
}
